Page 263 - Water Standards
P. 263

shall meet the following requirements:
                  1) The spacing between two circular seams in the straight seg⁃
                     ment shall be no less than 100mm and larger than twice
                     the pipe external diameter.
                  2) The distance between butt weld joints and the bending
                      point of the elbow pipes shall be no less than 100mm and
                      no less than the pipe external diameter.
                  3) The clear distance between the weld joints and supporting
                     or hanging brackets shall be no less than 50mm; pipes
                     which pass through the partition wall and the floor shall
                     have no welded junctions in the wall and floor.
                  4) There shall be no pores at the pipe weld joints; if the
                     pores have to be opened, the weld joints shall pass non⁃
                     destructive inspection.
                4  A bend radius of welded elbow pipe shall be no less than 1   5
           times the pipe diameter. There should not be less than four sections in
           a 90° elbow. The angle of the elbow axis shall be in accordance with
           the sample plate after welding  
                5  Pipeline embedding shall meet the following requirements:
                  1) Pipelines should not be connected by screw threads or
                      flanges.
                  2) For oil or gas pipelines, the method of embedded adapter
                     sleeves shall be used.
                  3) If the pipeline passes through an expansion joint, the
                      measures which are taken to protect the pipes shall meet
                      the design requirements.
                6    Installation position of an exposed pipe shall meet the
           following requirements:
                  1) The deviation of the installation position ( coordinates or
                     elevation) should not be larger than 10mm.
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